Compares to traditional guaiac tests like Hemoccult, HemoQuant more reliably measures fecal blood and more likely detects bleeding from patients with symptomatic colorectal neoplasms. The current study aims to (1) assess the validity of HemoQuant in detecting asymptomatic colorectal neoplasms and to compare this with Hemoccult result and (2) investigate the member of fecal specimens per test period which optimizes test validity. As these objectives can most efficiently be met using a population with target lesion prevalence, patients are studied who have previously had colorectal cancer and their first order relatives age 50 or older. Subjects are identified at North Center Cancer Treatment Group (NCCTG) centers and at the Mayo Clinic. Study assistants at the Mayo-based central office coordinate all subsequent operations including patient and physician correspondence, specimen handling, and data management. All fecal blood assays are done at Mayo laboratories. Over the period of study this will involve at least 75,000 patient and physician communications, the receipt and processing of 22,000 kits each containing three fecal specimens, and the management of 32 form letters. To accomplish this logistically complex task with minimal error, an automated system has been developed and is fully operational which integrates our patient data base, Laboratory Computer System, Surgical Pathology Computer System, and the Institutional Data Base via terminal, work processor, and electronic data transfer. After the first two years of funding (which represents about one year of accrual), 21% (356/700) of the post-resection patients originally projected for study needs have been accrued and 18.5% (2776/15,000) of first-order relatives have been accrued. Compliance to study procedures has exceeded 90% in registrants. Early observations suggest a prevalence yield of 33 colorectal neoplasms per 1000 subjects screened. Based on the projected accrual size of this disease-enriched population, the power to detect a meaningful difference in test performances is high. The operational objective for the remaining three years of study is to maximize accrual efficiency using the currently established automated management system.